Spark-arrester for locomotives



('No Model.)

T. J. McMINN. SPARK AR RESTER FOR LOGO MOTIVES.

No. 280,206. Patented June 26, 1883.

' the specific gravity'of the cinders overcom- .2isa horizontal section at 2 2. Fig. 3 is a I horizontal section at 3 3.

PATENT OFFICE.

THEODOB-E J. MCMINN, OF ST. Louis, MISSOURI.

ASPARK-AHRRESITER FORILOCOMOTIVES.

SPECIFICATION formingpart of Letters Patent No. 280,206, dated June 26, 1883.

Application filed November 15, 1882. (Nb model.)

To all whom it may concern 1 Be it known that I, THEODORE .I. McMINN, of the city of St. Louis, in the State of Missouri, have invented a certain new and useful Improvement in Spark-Arresters for Locomotive Smoke-Stacks, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, forming part of this specification.

My invention relates to that form of spark arr-ester in which a vertical shaft provided with a spiral flange is employed to convey the sparks up through a tube within the smokestack.

My improvement consists in important details of construction, which are intended to render such a device more useful. v

Figure 1 is an axial section of a locomotive smoke-stack, with side view of thespiral. Fig.

A shows part of the top of a locomotive smoke-chamber, to which the smoke-stack is secured in any suitable manner. The vertical steamjet is shown at B, as usual. The smoke-stack has a cylindrical shell, 0, with a contracted top, I). E is a cylindrical pipe or chimney-flue, bolted to a collar, L, within the shell 0, and concentric therewith. Between the shell 0 and flue or pipe E is an open-topped annular chamber, F, to receive the sparks and hot cinders. Within the pipe E and the part of shell C above the same is"a spiral flange, G, or thin worm, of sheet metal, supported on a vertical axial shaft, H, having bearing in cross-bars or spiders I J at bottom and top, secured to the collar L and top of the stack 0, respectively. The spiral G is shown extending from the bottom to the top of the cylindrical part 0 of the smoke-stack, the projection g extending over the annular chamber F.

The action of the revolving spiral G is twofold: First, it gives a centrifugal motion to the ascending smoke and cinders, and the cinders, being heavier than the smoke, are carried to the side of the flue E and to the shell 0 above the flue, over the upper edge, e, of the flue. At this point an eddy is formed, and

in g their upward momentum, they fall into the annular chamber F. The second function of the spiral is to regulate the upward passage of the products of combustion through the stack, for, as each jet of steam will accelerate the revolution of the spiral, the spiral will somewhat check the upward motion and pre vent the violent ejection of sparks from the stack. On the other hand, between the jets the spiral will, by its rapid rotation, assist the upward movement of the products of combustion in the stack. The edges of the spiral should not be in such near proximity to the wallsoof the stack as to prevent the upward passage of the smoke with sufficient freedom.

K are doors contiguous to the collar, at the base of and in the shell 0, to allow the removal of cinders from time to time from the chamber F. If preferred, pipes may be provided to conduct the cinders to any other place of discharge.

I claim as my invention- 1. In a spark-arrester, the combination of stack 0 and shell E, secured rigidly to the top of the body A, the spiders I J at the bottom of the inner shell and top of the stack, beneath the top, respectively, shaft H, mounted in said spiders, having thin spiral flange adapted to revolve independently of the shell, and the openings into the stack for removal of the cinders, as set forth.

2. a. The shaft H, provided with thin spiral flange G, having extended portion g, and the fixed shell having supporting-spider I, in combination with the stack G, having spider J, forming bearing for upper end of the shaft,

and a chamber, F, between the stack and shell,

over which the upper portion, 9, of the flange extends, as set forth.

3. The steam-jet B in vertical position, in combination with the shaft H, having spiral flange G, and shell E, independent of said shaft, the spiral flange entering the shell, substantially as shown.

THEODORE J. MCMINN.

Witnesses:

SAML. KNIGHT, GEO. H. KNIGHT. 

